Field of Invention
This invention relates to a method for treating cancer patients, in particular to methods for treating cancer patients with K-ras mutation.
Related Art
Metformin is isolated from Galega offivinalis, and Galega officinalis was used for the treatment of diabetes for centuries. In the 1920s, the guanidine compound was discovered in Galega extracts, and, by animal experiments, the guanidine compound has been confirmed to be the main active ingredient to reduce blood glucose concentration. So far, we've known the mechanism of metformin or the medically acceptable salt thereof is to enhance glucose uptake and carbohydrates catabolism in muscle cells, and to suppress glucose production by the liver. Metformin thus has an antihyperglycemic effect, and has been widely used in treating type 2 (non-insulin dependent) diabetes mellitus.
Some patients with the type 2 diabetes mellitus have extraordinary high risk of having one of the three cancers at the same time: colorectal cancer, breast cancer and pancreatic cancer. Some studies show that administration of metformin or the pharmaceutically acceptable salt thereof can generally reduce the risk of developing cancer in the patients with type 2 diabetes mellitus. In other words, among the patients with type 2 diabetes mellitus, those who are administered with metformin or the pharmaceutically acceptable salt thereof have less risk of developing colorectal cancer, breast cancer or pancreatic cancer than those who are not administered.
On the other hand, the sodium butyrate is a histone deacetylase inhibitor (HDACi). The phenomenon of the histone deacetylase (HDAC) overexpression widely exists in many kinds of cancer; therefore, the sodium butyrate is considered as a substance with a great therapeutic potential, and applied in many cell or animal experiments. Current studies have found that the sodium butyrate inhibits growth of some specific cancer cell and induces apoptosis of some specific cancer cell; thereby the sodium butyrate has an efficacy of slowing tumor growth. Furthermore, sodium butyrate is also considered as a protective agent of the intestinal tract, which can repair the intestinal mucosa and treat the inflammation of the intestinal tract, thereby to reduce the risk of colitis oncogenesis. Furthermore, sodium butyrate also has been found to be able to prevent the developing of breast cancer.
In summary, currently studies confirm that metformin or the pharmaceutically acceptable salt thereof, or the sodium butyrate is individually effective for some specific cancer, to a certain degree. However, the therapeutic effect of each compound is only has their respective effect. Besides, metformin is still mostly used in the treatment of diabetes. As for reducing the morbidity of colorectal cancer, breast cancer or pancreatic cancer, due to the mechanism is not clear, such efficacy has not been expected. Therefore, further studies of metformin and sodium butyrate still make no breakthrough for now.
However, especially for cancer patients with K-ras mutation, current drug has no significant therapeutic effect, and the clinical studies also confirm using metformin or the pharmaceutically acceptable salt thereof, or using sodium butyrate, is not much help for relieving or ameliorating the symptoms of the K-ras mutation cancer.